35 research outputs found
MODELLING OF ROUGH RICE SOLAR DRYING UNDER NATURAL CONVECTION
In this study, the sun drying behaviour of aromatic rough rice was investigated. Drying experiments were conducted at three different seasons in Ivory Coast. The drying data were fitted to ten different mathematical models. Among the models, the Two-term model was found to best explain thin layer open sun drying behaviour of the rice. The performance of these models was investigated by comparing the determination of coefficient (R²), sum square error (SSE) and root mean square error (RMSE) between the observed and predicted moisture ratios. The effective diffusivity coefficient of moisture transfer during drying, computed on the basis of Fick’s law, was within the range of 8.345.10-12 and 4.517.10-11m2.s-1. In addition, the activation energy was estimated to 68.255 Kj.mol-1
EVALUATION DES METAUX TRACES, PESTICIDES ET PLASTIFIANTS DANS LES PRODUITS MARAICHERS (GOMBO, CORETE POTAGERE, EPINARD ET AUBERGINE) DANS LAVALLEE DU NIEKI, SUD-EST DE LA COTE D’IVOIRE
A grade assessment study of metal trace metals (Cu, Zn, Cd and Pb), pesticides and plasticizers in market garden crops (Abelmoschus sp, Corchoruus tridens, Basela alba, Solanum aethiopicum) was performed in Niéki Valley in South-East of Côte d'Ivoire. This study found that trace metals found in the leaves and fruits grown on the different sampling sites are copper (Cu), Zinc (Zn), cadmium (Cd) and Lead (Pb). The Cu was accumulated in the leaves and the fruits. The Cu was accumulated in both the leaves and the fruits. The Cu concentrations in different plants far exceeded thelevels recommendedby the FAO (1 mg.kg-1). The Pb concentrations in different plants were between 106 and 109mg.kg- 1on all sites, far exceeding the thresholds set by the FAO (0.1 mg.kg-1of fresh material). Analyses of various plants showed that most elements are found pesticide family Pyrethroids (Bifenthrin, Deltamethrin and cyhalothrin) and a plasticizerof the phthalate family (1,2Benzenedicarboxylicacid, bis (2- ethylhexyl) ester). Doses of Bifenthrin determined in plants exceeded the acceptable daily intake (ADI) or (0.015 mg.kg-1), except in the case of Abelmoschus sp where these levels remain below the acceptable daily intake
Effects of Wheat Flour Dough’s Viscoelastic Level by Adding Glucose Oxidase on its Dynamic Shear Properties whatever the Strain Modes
The objective of this work was to study the effects of wheat flour dough’s viscoelastic level by adding glucose oxidase (Gox) on its rheological properties at dynamic shear strain mode to predict the final product quality. Dough does display a linear viscoelastic domain. Glucose oxidase (Gox) was added to dough in order to enhance its viscoelasticity and to take into account the possible effects of this viscoelasticity on the results. Whatever the types of dough strain used G’ increased, tan δ decreased and led to less sticky dough. Wheat flour dough, an increase in G’ with extension may be associated to a strain-hardening phenomenon but the role of dough viscoelasticity is discussed
Behavior Of Manganese Ion In Basic Medium: Consequence For The Measurement Of Enzymatic Activities Using Nitrophenyl Derivatives
The use of nitrophenyl derivatives in the determination of the
influence of manganese ion on catalytic activities of glycosidases and
phosphatases remains a problem. In fact, in this study, adding
manganese chloride or manganese sulfate to sodium hydroxyde or sodium
carbonate in aqueous solution yielded secondary reactions. These
secondary reactions affected the absorbance for wavelengths varying
between 400-420 nm. This chemical behavior did not allow reliable
results in determining the influence of manganese ion on glycosidase
and phosphatase activities, when nitrophenyl derivatives were used as
substrates. This study showed that this problem could be avoided when
natural substrates such as disaccharides (glycosidases) and
phosphorylglycosides (phosphatases) were used in enzymatic tests
EVALUATION DES METAUX TRACES, PESTICIDES ET PLASTIFIANTS DANS LES PRODUITS MARAICHERS (GOMBO, CORETE POTAGERE, EPINARD ET AUBERGINE) DANS LAVALLEE DU NIEKI, SUD-EST DE LA COTE D’IVOIRE
A grade assessment study of metal trace metals (Cu, Zn, Cd and Pb), pesticides and plasticizers in market garden crops (Abelmoschus sp, Corchoruus tridens, Basela alba, Solanum aethiopicum) was performed in Niéki Valley in South-East of Côte d'Ivoire. This study found that trace metals found in the leaves and fruits grown on the different sampling sites are copper (Cu), Zinc (Zn), cadmium (Cd) and Lead (Pb). The Cu was accumulated in the leaves and the fruits. The Cu was accumulated in both the leaves and the fruits. The Cu concentrations in different plants far exceeded thelevels recommendedby the FAO (1 mg.kg-1). The Pb concentrations in different plants were between 106 and 109mg.kg- 1on all sites, far exceeding the thresholds set by the FAO (0.1 mg.kg-1of fresh material). Analyses of various plants showed that most elements are found pesticide family Pyrethroids (Bifenthrin, Deltamethrin and cyhalothrin) and a plasticizerof the phthalate family (1,2Benzenedicarboxylicacid, bis (2- ethylhexyl) ester). Doses of Bifenthrin determined in plants exceeded the acceptable daily intake (ADI) or (0.015 mg.kg-1), except in the case of Abelmoschus sp where these levels remain below the acceptable daily intake
Évaluation De La Vulnerabilite A La Pollution D'une Eau De Surface Destinee A L'adduction D'eau Potable D'une Metropole. Cas De La Lagune Aghein A Abidjan, (Sud De La Cote D'ivoire)
The lagoon that is the subject of this study, was chosen as drinking water alternative source of supply for the city of Abidjan. However, this language is shown in a very favorable area of forest to agriculture. We observe large rubber plantations, food and oil palm crops spread throughout the lagoon basin. Also, fertilizers injected into these plantations, as well as releases from industries and homes they are potential sources of pollution of the lagoon. According Humbert (2012), this pollution is reflected in particular by widespread concentration of nitrates and pesticides. Given these observed problems related to the quality of this resource, this study was initiated. Its objective is to develop a methodology based on the functionality of a Geographic Information System (GIS) to assess the degree of threat to what the Aghein lagoon faces through the completion of a vulnerability map at pollution. The method used here is a spatial analysis model incorporating several parameters including the slope, land cover, soil type, runoff and drainage density. These parameters have been previously defined, prioritized and weighted, and then integrated into a GIS. The resulting map shows five classes of vulnerability indices to pollution of the lagoon Aghein. They are: very small classes, low, medium, high and very high. These indices highlight the areas from which the lagoon is threatened
Epidemiological, Clinical, and Paraclinic Aspect of Cutaneous Sarcoidosis in Black Africans
The specific objectives were to identify the epidemiology of cutaneous sarcoidosis and describe the clinical and laboratory aspects of the disease. Materials and Methods. We performed a descriptive cross-sectional study involving 24 referred cases of cutaneous sarcoidosis in 25 years (1990–2014) collected at Venereology Dermatology Department of the University Hospital of Treichville (Abidjan) both in consultation and in hospitalization. Results. The hospital frequency was one case per year. The average age was 42 years, ranging from 9 to 64. The sex ratio was 1. The shortest time interval between the appearance of the skin lesion and consultation of Dermatology Department at CHU Treichville was 3 months. The elementary lesions were represented primarily by a papule (18 cases), placard (3 cases), and nodule (2 cases) and mainly sat on the face and neck in 8 cases (38%). Extra cutaneous lesions were dominated by ganglion and respiratory involvement with 5 cases each followed by musculoskeletal damage in 3 cases. Chest radiography showed abnormality in 13 cases (54%). The pulmonary function test performed in 13 patients found 7 cases (54%) having restrictive ventilatory syndrome and 6 cases (46%) being normal. A tuberculin anergy was found in 11 cases (61%)
Restoration of fertility of gleyic fluvisols to increase rice yields using shellfish products in Toumbokro, Côte d'Ivoire
A study designed to characterize the effects of shellfish products on the
chemical properties of fluvisols gleyic and yield of rice was carried out in
Toumbokro, Yamoussoukro’s region, Côte d'Ivoire. The work has been
focused on soil amendment by three types of shells (Achatina spp Donax spp
and Ostrea spp). Three doses of shellfish products (500, 1000 and 1500 kg.ha-
1) and NPK fertilizer were tested in a split-plot design with three repetitions. At
ground level, the study showed that the shellfish products have positive effects
very marked on all the physical and chemical characteristics. The effects of
these shellfish products on the richness of the soil occur gradually. The
increase of pH, due to the products made, creates a condition favorable to
microorganisms that become active and mineralize sufficient organic
substances. The study indicates that shellfish products induce high levels of
production of rice cultivation. The average of yield of the experiments carried
out is set at 5.41 t.ha-1 in Toumbokro. These performances, never recorded in
subsistence agriculture, are explained by the effective correction of mineral
deficiencies unsuspected soil by the flow of shellfish products. All the
variables studied define the contribution of 1000 kg.ha-1 shredded shells of
Achatina spp, as the optimum for soil amendment
Cartographie des zones potentielles de recharge de la nappe de Bonoua (sud-est de la Côte d’Ivoire)
Ce travail a pour objectif de déterminer les zones favorables à la recharge de la nappe de Bonoua par approche cartographique et système d’information géographique (SIG). La détermination de ces zones potentielles de recharge de la nappe a nécessité le croisement des informations spatiales relatives aux différents paramètres régissant la recharge qui sont exprimés en cartes thématiques. Une reclassification suivie d’une pondération de ces paramètres a été faite selon leur degré d’implication dans le processus de recharge par l’analyse multicritère Analytical Hierarchy Process (AHP) de Saaty. Ils sont par la suite intégrés dans un SIG afin d’établir la carte des zones potentielles de recharge de la nappe. L’analyse de cette carte a révélé cinq classes, dont une classe de bonne recharge couvrant 66 % de la zone étudiée. Celle-ci est localisée en majorité dans la partie centrale de la nappe, précisément dans le Continental Terminal, constitué principalement de sables grossiers avec des pentes relativement faibles où le sol est occupé par des cultures industrielles. Les zones de faible recharge (34 % de la zone étudiée) sont localisées sur les bordures ouest et est de la zone d’étude sur les sols hydromorphes. Cette carte de répartition spatiale de la recharge peut être considérée comme un support d’aide à la décision, notamment pour la gestion de la ressource en eau et l’analyse de la vulnérabilité des eaux souterraines. Les zones de recharge préférentielle méritent une attention particulière des autorités par l’instauration de mesures de protection.This work aims at the determination of favourable areas for the recharge of the Bonoua aquifer, using a cartographic approach and a Geographic Information System (GIS). The determination of these potential recharge areas of the aquifer required the integration of spatial information related to different parameters regulating the recharge, which are represented by thematic maps. A new classification has been done with a weighting of these parameters according to their degree of involvement in the recharge process, using a multicriterion analysis such as the Analytical Hierarchy Process (AHP) of Saaty. In order to establish the map of potential recharge areas for the Bonoua aquifer, the weighting parameters were incorporated in the GIS. Analysis of the resulting map revealed five classes, included one class of better recharge covering 66% of the studied area. This dominant class is located at the central part of the aquifer, especially in the Terminal Continental, which is largely composed of coarse sands with relatively shallow slopes, where the land is used by industrial cultures. The areas of low recharge (34% of the studied area) are located at the western and eastern borders of the studied area on hydromorphic soils. This map showing the spatial distribution of the recharge areas could be considered as a decision-making tool, especially for management of the water resource and analysis of groundwater vulnerability. The preferential recharge areas need particular attention from authorities in order to ensure protection of the aquifer
Prévention du brunissement enzymatique de l’aubergine violette (Solanum melongena L.) par traitement thermique : analyses cinétiques et thermodynamiques: Prevention of enzymatic browning of violet eggplant (Solanum melongena L.) by heat treatment: kinetic and thermodynamic analyses
Le brunissement enzymatique est associé à l'action des polyphénol oxydases (PPO) et des peroxydases (POD). Les produits de ces enzymes provoquent des changements indésirables de couleur et de saveur des aubergines transformées. Une dopamine oxydase responsable du brunissement enzymatique a été isolée de l’aubergine violette (Solanum melongena L.). Ainsi, l’inactivation thermique et l’analyse thermodynamique ont été étudiées sur une base cinétique afin de contrôler ce phénomène physiologique. Les études cinétiques ont montré que l’inactivation thermique de l’activité dopamine oxydase de l’aubergine violette suivait une cinétique de premier ordre aux températures comprises entre 35 – 80 °C, avec des constantes de vitesse (k) comprise entre 0,0101 ± 0,0001 et 0,0865 ± 0,0004 min-1. Les temps de réduction décimale (D) et k ont diminué et augmenté respectivement avec l’augmentation de la température, indiquant une inactivation plus rapide de la dopamine oxydase à des températures plus élevées. Les résultats suggèrent que dopamine oxydase est une enzyme relativement thermostable avec une constante de résistance (Z) de 50.25 ± 0,7 °C et une énergie d'activation (Ea) de 40.65 ± 0,6 kJmol-1. Les résultats thermodynamiques ont indiqué que les réactions d'oxydation étaient : non spontanées (ΔG > 0), légèrement endothermiques (ΔH > 0) et réversibles (ΔS < 0). Ces données cinétiques peuvent être utilisées dans la prévention du brunissement enzymatique de la pulpe d’aubergine violette par l'inactivation thermique de l'enzyme.
Enzymatic browning is associated with the action of polyphenol oxidases (PPO) and peroxidases (POD). The products of these enzymes cause undesirable changes of color and flavor of processed eggplant products. A dopamine oxidase responsible for enzymatic browning was isolated from violet eggplant (Solanum melongena L.). Thus, thermal inactivation and thermodynamic analysis were studied on a kinetic basis to control this physiological phenomenon. Kinetic studies showed that thermal inactivation of dopamine oxidase activity in purple eggplant followed first-order kinetics at temperatures between 35 - 80 °C, with speed constants (k) values between 0.0101 ± 0.0001 and 0.0865± 0.0004 min-1. The decimal reduction times (D) and k values decreased and increased, respectively, with increasing temperature, indicating more rapid inactivation of dopamine oxidase at higher temperatures. The results suggest that dopamine oxidase is a relatively thermostable enzyme with a resistance constant (Z) value of 50.25 ± 0.7 °C and an activation energy (Ea) of 40.65 ± 0.6 kJmol-1. Thermodynamic results indicated that the oxidation reactions were: non-spontaneous (ΔG > 0), slightly endothermic (ΔH > 0), and reversible (ΔS < 0). These kinetic data can be used in the prevention of enzymatic browning of purple eggplant pulp by thermal inactivation of the enzyme